Aetna considers cold laser therapy (also known as low level laser therapy) experimental and investigational because there is inadequate evidence of the effectiveness of cold laser therapy in wound healing, pain relief, or for other indications such as physical therapy, musculoskeletal dysfunction, arthritis, lymphedema, and neurological dysfunctions.

See also CPB 604 - Infrared Therapy.

Low-energy lasers (also known as cold lasers) have been promoted as an effective way to produce analgesia and accelerate healing of a variety of clinical conditions.

By definition, low energy laser therapy uses irradiation intensities that induce minimal temperature elevation (not more than 0.1-0.5°C), if any. For practical purposes, this restricts treatment energies to a few J/cm2 and laser powers to 50 mW or less.

Despite these constraints, a wide variety of types of lasers, treatment schedules, and techniques have been used. Consequently, apparently conflicting results from studies of low-intensity lasers may not be in conflict, and may represent fundamental, but poorly understood, differences in treatment approaches.

Although the results from large, uncontrolled, open trials of low-energy lasers in inducing wound healing have shown benefit, controlled trials have shown little or no benefit. The analgesic effects of low-energy lasers have been most intensely studied in rheumatoid arthritis. Recent well-designed, controlled studies have found no benefit from low energy lasers in relieving pain in rheumatoid arthritis or other musculoskeletal conditions. Furthermore, although positive effects were found in some earlier studies, it was not clear that the pain relief achieved was large enough to have either clinical significance or to replace conventional therapies.

Published systematic reviews of the evidence have concluded that there is a lack of adequate evidence of effectiveness of cold laser therapy for treatment of chronic wounds (e.g., Schneider and Hailey, 1999; Cullum and Petherick, 2007; Flemming and Cullum, 1999; Samson et al, 2004; Simon et al, 2004; Wang, 2004; Nelson and Jones, 2006), arthritis (Brosseau et al, 2007; Brosseau et al, 2005; Marks and de Palma, 1999; Puett and Griffin, 1994; Wang, 2004), tuberculosis (Vlassov et al, 2006; Ziganshina and Garner, 2005), tinnitus (Waddell, 2004), pain (Gross et al, 1998; van der Heijden et al, 2002; Binder, 2002; Speed, 2006; Green et al, 2003), smoking cessation (White et al, 2006), epicondylitis (Chapell, et al., 2002), Achilles tendinitis (McLauchlan et al, 2001), plantar heel pain (Crawford and Thomson, 2003; Landorf and Menz, 2007), back pain (Yousefi-Nooraie, et al., 2008),  and other musculoskeletal disorders (de Bie et al, 1998; Abdulwadud, 2001; Ohio BWC, 2004; Wang, 2004). Systematic evidence reviews have also concluded that low-energy laser therapy (e.g., Microlight 830, Microlight Corporation of America, Missouri City, TX) is ineffective in treating carpal tunnel syndrome (Gerritsen et al, 2002; O'Connor et al, 2003; Ohio BWC, 2004; Wang, 2004; CTAF, 2006).

A recent study (Hirschl et al, 2004) evaluated the effectiveness of low-level laser therapy in patients with primary Raynaud's phenomenon (n = 48). Laser and sham therapy each were applied 5 days a week for 3 weeks. The authors found that low-level laser therapy reduced the frequency and severity of Raynaud attacks. The findings of this study are interesting but need to be validated by further investigation with more patients and follow-up.

Kreisler et al (2004) assessed the effect of low-level laser application on post-operative pain after endodontic surgery in a double-blind, randomized clinical study. Fifty-two healthy adults undergoing endodontic surgery were included into the study. After suturing, 26 patients had the operation site treated with an 809 nm-GaAlAs-laser at a power output of 50 mW and an irradiation time of 150 s. Laser treatment was simulated in another 26 patients. Patients were instructed to evaluate their post-operative pain on 7 days following surgery by means of a visual analogue scale. The results revealed that the pain level in the laser-treated group was lower than in the placebo group throughout the 7 day follow-up period. The differences, however, were significant only on the first post-operative day. The authors stated that low-level laser therapy can be beneficial for the reduction of post-operative pain. However, its clinical effectiveness and applicability with regard to endodontic surgery need further investigation, especially in terms of the optimal energy dosage and the number of laser treatments needed after surgery.

In a randomized controlled study, Bingol et al (2005) examined the effect of low-power gallium-arsenide laser treatment on the patients with shoulder pain. A total of 40 patients with shoulder pain and complied with the selection criteria were included in the study. They were randomly assigned into 2 groups: (i) laser treatment (n = 20), and (ii) control (n = 20). In group (i), patients were given laser treatment and an exercise protocol for 10 sessions during a period of 2 weeks. In group (ii), placebo laser and the same exercise protocol was given for the same period. Patients were evaluated according to the parameters of pain, palpation sensitivity, algometric sensitivity, and shoulder joint range of motion before and after treatment. Analysis of measurement results within each group showed a significant post-treatment improvement for some active and passive movements in both groups, and also for algometric sensitivity in group (i) (p < 0.05 to 0.01). Post-treatment palpation sensitivity values showed improvement in 17 patients (85%) for group (i) and 6 patients (30%) for group (ii). Comparison between two groups showed superior results (p < 0.01 and p < 0.001) in group (i) for the parameters of passive extension and palpation sensitivity but no significant difference for other parameters. These researchers concluded that this study have shown better results in palpation sensitivity and passive extension, but no significant improvement in pain, active range of motion, and algometric sensitivity in laser treatment group compared to the control group in the patients with shoulder pain.

Markovic and Todorovic (2007) compared the effectiveness of dexamethasone and low-power laser (LPL) after surgical removal of impacted lower third molars under local anesthesia (2 % lidocaine / epinephrine). A total of 120 healthy patients were divided into 4 groups of 30 each: (i) group 1 received LPL irradiation immediately after operation (energy output 4 J/cm2 with constant power density of 50 mW, wavelength 637 nm); (ii) group 2 also received intramuscular (i.m.) injection of 4 mg dexamethasone (Dexason) into the internal pterygoid muscle; (iii) group 3 received LPL irradiation supplemented by systemic dexamethasone, 4 mg i.m. in the deltoid region, followed by 4 mg of dexamethasone intra-orally 6 hours post-operatively; and (iv) control group received only the usual post-operative recommendations (i.e., cold packs, soft diet, etc.). LPL irradiation with local use of dexamethasone (group 2) resulted in a statistically significant reduction of post-operative edema in comparison to the other groups. No adverse effects of the procedure or medication were observed. The authors concluded that low-power laser irradiation after lower third molar surgery can be recommended to minimize swelling. The effect is enhanced by simultaneous local intramuscular use of dexamethasone. The drawbacks of this study were two-fold: (i) the effects of low-power laser, if any, was confounded by the simultaneous use of dexamethasone, and (ii) while the combination of low-power laser and dexamethasone achieved a statistical significant reduction in edema, its clinical benefit is unclear.

Kaviani and colleagues (2006) examined the effects of low level laser therapy (LLLT) in the treatment of post-mastectomy lymphedema.  A total of 11 women with unilateral post-mastectomy lymphedema were enrolled in a double-blind controlled trial.  Patients were randomly assigned to laser and sham groups and received laser or placebo irradiation (Ga-As laser device with a wavelength of 890 nm and fluence of 1.5 J/cm2) over the arm and axillary areas.  Changes in patients' limb circumference, pain score, range of motion, heaviness of the affected limb, and desire to continue the treatment were measured before the treatment and at follow-up sessions (weeks 3, 9, 12, 18, and 22) and were compared to pre-treatment values.  Results showed that of the 11 enrolled patients, 8 completed the treatment sessions.  Reduction in limb circumference was detected in both groups, although it was more pronounced in the laser group up to the end of 22nd week.  Desire to continue treatment at each session and baseline score in the laser group was greater than in the sham group in all sessions.  Pain reduction in the laser group was more than in the sham group except for the weeks 3 and 9.  No substantial differences were seen in other two parameters between the two treatment groups.  The authors concluded that despite the encouraging results, further studies of the effects of LLLT in management of post-mastectomy lymphedema should be undertaken to determine the optimal physiological and physical parameters to obtain the most effective clinical response.

In a systematic review of common conservative therapies for arm lymphoedema secondary to breast cancer treatment, Moseley et al (2007) stated that secondary arm lymphoedema is a chronic and distressing condition which affects a significant number of women who undergo breast cancer treatment.  A number of health professional and patient instigated conservative therapies have been developed to help with this condition, but their comparative benefits are not clearly known.  This systematic review undertook a broad investigation of commonly instigated conservative therapies for secondary arm lymphoedema including; complex physical therapy, manual lymphatic drainage, pneumatic pumps, oral pharmaceuticals, LLLT, compression bandaging and garments, limb exercises and limb elevation.  It was found that the more intensive and health professional based therapies, such as complex physical therapy, manual lymphatic drainage, pneumatic pump and laser therapy generally yielded the greater volume reductions, whilst self-instigated therapies such as compression garment wear, exercises and limb elevation yielded smaller reductions.  All conservative therapies produced improvements in subjective arm symptoms and quality of life issues, where these were measured.  Despite the identified benefits, there is still the need for large scale, high level clinical trials in this area.

Information on lymphedema from the BC Cancer Agency (2007) notes that laser therapy "may or may not work but need[s] further study."